In stress-controlled load increase and single step tests besides the plastic strain amplitude
the changes of the temperature and the electrical resistance caused by cyclic plastic deformation
were measured. Temperature and resistance measurements don’t require a defined gage length and
can be applied also on components even under service loading to ensure economic and safe
operation conditions. On the basis of Morrow and Basquin equations a physically based fatigue life
calculation “PHYBAL” was developed. This new short-time procedure allows a rapid and precise
calculation of Woehler curves with data of one load increase and two single step tests.